lib/freetype/include/freetype/cache/ftccmap.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftccmap.h                                                              */
   4 /*                                                                         */
   5 /*    FreeType charmap cache (specification).                              */
   6 /*                                                                         */
   7 /*  Copyright 2000-2001 by                                                 */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18
  19 #ifndef __FTCCMAP_H__
  20 #define __FTCCMAP_H__
  21
  22 #include <ft2build.h>
  23 #include FT_CACHE_H
  24
  25
  26 FT_BEGIN_HEADER
  27
  28
  29   /*************************************************************************/
  30   /*                                                                       */
  31   /* <Section>                                                             */
  32   /*    cache_subsystem                                                    */
  33   /*                                                                       */
  34   /*************************************************************************/
  35
  36   /*************************************************************************/
  37   /*                                                                       */
  38   /* @type:                                                                */
  39   /*    FTC_CmapCache                                                      */
  40   /*                                                                       */
  41   /* @description:                                                         */
  42   /*    An opaque handle used to manager a charmap cache.  This cache is   */
  43   /*    to hold character codes -> glyph indices mappings.                 */
  44   /*                                                                       */
  45   typedef struct FTC_CMapCacheRec_*  FTC_CMapCache;
  46
  47
  48   /*************************************************************************/
  49   /*                                                                       */
  50   /* @type:                                                                */
  51   /*    FTC_CMapDesc                                                       */
  52   /*                                                                       */
  53   /* @description:                                                         */
  54   /*    A handle to an @FTC_CMapDescRec structure used to describe a given */
  55   /*    charmap in a charmap cache.                                        */
  56   /*                                                                       */
  57   /*    Each @FTC_CMapDesc describes which charmap (of which @FTC_Face) we */
  58   /*    want to use in @FTC_CMapCache_Lookup.                              */
  59   /*                                                                       */
  60   typedef struct FTC_CMapDescRec_*  FTC_CMapDesc;
  61
  62
  63   /*************************************************************************/
  64   /*                                                                       */
  65   /* @enum:                                                                */
  66   /*    FTC_CMapType                                                       */
  67   /*                                                                       */
  68   /* @description:                                                         */
  69   /*    The list of valid @FTC_CMap types.  They indicate how we want to   */
  70   /*    address a charmap within an @FTC_FaceID.                           */
  71   /*                                                                       */
  72   /* @values:                                                              */
  73   /*    FTC_CMAP_BY_INDEX ::                                               */
  74   /*      Address a charmap by its index in the corresponding @FT_Face.    */
  75   /*                                                                       */
  76   /*    FTC_CMAP_BY_ENCODING ::                                            */
  77   /*      Use a @FT_Face charmap that corresponds to a given encoding.     */
  78   /*                                                                       */
  79   /*    FTC_CMAP_BY_ID ::                                                  */
  80   /*      Use an @FT_Face charmap that corresponds to a given              */
  81   /*      (platform,encoding) ID.  See @FTC_CMapIdRec.                     */
  82   /*                                                                       */
  83   typedef enum  FTC_CMapType_
  84   {
  85     FTC_CMAP_BY_INDEX    = 0,
  86     FTC_CMAP_BY_ENCODING = 1,
  87     FTC_CMAP_BY_ID       = 2
  88
  89   } FTC_CMapType;
  90
  91
  92   /*************************************************************************/
  93   /*                                                                       */
  94   /* @struct:                                                              */
  95   /*    FTC_CMapIdRec                                                      */
  96   /*                                                                       */
  97   /* @description:                                                         */
  98   /*    A short structure to identify a charmap by a (platform,encoding)   */
  99   /*    pair of values.                                                    */
 100   /*                                                                       */
 101   /* @fields:                                                              */
 102   /*    platform :: The platform ID.                                       */
 103   /*                                                                       */
 104   /*    encoding :: The encoding ID.                                       */
 105   /*                                                                       */
 106   typedef struct  FTC_CMapIdRec_
 107   {
 108     FT_UInt  platform;
 109     FT_UInt  encoding;
 110
 111   } FTC_CMapIdRec;
 112
 113
 114   /*************************************************************************/
 115   /*                                                                       */
 116   /* @struct:                                                              */
 117   /*    FTC_CMapDescRec                                                    */
 118   /*                                                                       */
 119   /* @description:                                                         */
 120   /*    A structure to describe a given charmap to @FTC_CMapCache.         */
 121   /*                                                                       */
 122   /* @fields:                                                              */
 123   /*    face_id    :: @FTC_FaceID of the face this charmap belongs to.     */
 124   /*                                                                       */
 125   /*    type       :: The type of charmap, see @FTC_CMapType.              */
 126   /*                                                                       */
 127   /*    u.index    :: For @FTC_CMAP_BY_INDEX types, this is the charmap    */
 128   /*                  index (within a @FT_Face) we want to use.            */
 129   /*                                                                       */
 130   /*    u.encoding :: For @FTC_CMAP_BY_ENCODING types, this is the charmap */
 131   /*                  encoding we want to use. see @FT_Encoding.           */
 132   /*                                                                       */
 133   /*    u.id       :: For @FTC_CMAP_BY_ID types, this is the               */
 134   /*                  (platform,encoding) pair we want to use. see         */
 135   /*                  @FTC_CMapIdRec and @FT_CharMapRec.                   */
 136   /*                                                                       */
 137   typedef struct  FTC_CMapDescRec_
 138   {
 139     FTC_FaceID    face_id;
 140     FTC_CMapType  type;
 141
 142     union
 143     {
 144       FT_UInt        index;
 145       FT_Encoding    encoding;
 146       FTC_CMapIdRec  id;
 147
 148     } u;
 149
 150   } FTC_CMapDescRec;
 151
 152
 153   /*************************************************************************/
 154   /*                                                                       */
 155   /* @function:                                                            */
 156   /*    FTC_CMapCache_New                                                  */
 157   /*                                                                       */
 158   /* @description:                                                         */
 159   /*    Creates a new charmap cache.                                       */
 160   /*                                                                       */
 161   /* @input:                                                               */
 162   /*    manager :: A handle to the cache manager.                          */
 163   /*                                                                       */
 164   /* @output:                                                              */
 165   /*    acache  :: A new cache handle.  NULL in case of error.             */
 166   /*                                                                       */
 167   /* @return:                                                              */
 168   /*    FreeType error code.  0 means success.                             */
 169   /*                                                                       */
 170   /* @note:                                                                */
 171   /*    Like all other caches, this one will be destroyed with the cache   */
 172   /*    manager.                                                           */
 173   /*                                                                       */
 174   FT_EXPORT( FT_Error )
 175   FTC_CMapCache_New( FTC_Manager     manager,
 176                      FTC_CMapCache  *acache );
 177
 178
 179   /*************************************************************************/
 180   /*                                                                       */
 181   /* @function:                                                            */
 182   /*    FTC_CMapCache_Lookup                                               */
 183   /*                                                                       */
 184   /* @description:                                                         */
 185   /*    Translates a character code into a glyph index, using the charmap  */
 186   /*    cache.                                                             */
 187   /*                                                                       */
 188   /* @input:                                                               */
 189   /*    cache     :: A charmap cache handle.                               */
 190   /*                                                                       */
 191   /*    cmap_desc :: A charmap descriptor handle.                          */
 192   /*                                                                       */
 193   /*    char_code :: The character code (in the corresponding charmap).    */
 194   /*                                                                       */
 195   /* @return:                                                              */
 196   /*    Glyph index.  0 means "no glyph".                                  */
 197   /*                                                                       */
 198   /* @note:                                                                */
 199   /*    This function doesn't return @FTC_Node handles, since there is no  */
 200   /*    real use for them with typical uses of charmaps.                   */
 201   /*                                                                       */
 202   FT_EXPORT( FT_UInt )
 203   FTC_CMapCache_Lookup( FTC_CMapCache  cache,
 204                         FTC_CMapDesc   cmap_desc,
 205                         FT_UInt32      char_code );
 206
 207   /* */
 208
 209
 210 FT_END_HEADER
 211
 212
 213 #endif /* __FTCCMAP_H__ */
 214
 215
 216 /* END */